Delta Force is the U.S. military's most elite tactical combat group. Yet the government refuses to deny its existence. Does a well-funded secret force that, allegedly, answers only to the president make the U.S. more secure or more vulnerable? See more »

Ever heard of a military operation run out of a hollowed-out mountain? Welcome to NORAD, a defense command that monitors air and space for potential attacks on the U.S. Learn about NORAD and the unique location for the NORAD headquarters. See more »

The U.S. Army Rangers are an oddity of the U.S. military special operations forces. Though they can trace their lineage as far back as colonial times, they didn't become a permanent presence in the military until the 1970s. See more »

John F. Kennedy called the green beret "a symbol of excellence, a badge of courage, a mark of distinction in the fight for freedom" -- a nod to the most formidable arm of the U.S. military. The Green Berets, or Special Forces, are America's first line of defense around the world. See more »

For most of us, "special ops" is what we see in the movies: soldiers trained to kill using their thumb; Charlie Sheen carrying a semi-automatic. But special operations forces are for real, and the U.S. Navy version -- the SEALs -- completes some of the most dangerous military missions. How much do you know about this elite team of fighters? See more »

The U.S. Air Force is the youngest American military branch, forming in the 20th century after the invention of the airplane. Tasked with protecting the nation's skies and supporting ground troops, the Air Force relies on the most technologically advanced military aircraft in the world. See more »